Origin: Latin prefix pre-
Predominantly has 2 different meanings across 1 category:
much greater in number or influence
"the patients are predominantly indigenous"
In a predominant manner. Most commonly or frequently by a large margin.
"The survey results were predominantly positive, with over eighty percent of respondents expressing satisfaction."
In plain English: Predominantly means something is mostly true or makes up the largest part of a group.
"The crowd was predominantly made up of young people celebrating the festival."
Usage: Avoid using "predominantly" when you simply mean "mostly," as the former implies a stronger, often overwhelming majority than the latter suggests. It is also slightly more formal than alternatives like "mainly" or "primarily."
The word predominantly comes from combining the adjective predominant with the suffix -ly to form an adverb. It entered English as a straightforward grammatical construction without any shift in its core meaning of being found or occurring most frequently.